subscription.endEventReceived implemented for some entry points (orders, positions, market scanner)
use of rxjs.hasError removed as it is deprecated
controller.resume on connection changed according to IB documentation (Important: The IBApi.EWrapper.nextValidID callback is commonly used to indicate that the connection is completed and other messages can be sent from the API client to TWS. There is the possibility that function calls made prior to this time could be dropped by TWS.)